Conventional testing of CMOS (complementary metal-oxide-silicon) image scan devices makes use of a halogen lamp to provide light for testing. This arrangement has significant disadvantages, including large size, significant required maintenance and difficulty in reconfiguring test setups. These problems become especially acute in the context of wafer-scale device testing, where a light source having a diameter as high as 300 mm may be required. Accordingly, it would be an advance in the art to provide an improved light source/probe card for testing optoelectronic devices.